I fixed in a bug in the way that the center scrollbar
In the current version, if you click on the center
scrollbar to drag
it, it will warp the scrollbar so that the top of it is
2 pixels above
the click point. Since the user probably didn't click
his mouse 2
pixels below the top of the scrollbar, this causes an
of the scrolbar whenever it's clicked. I fixed this.
Search for the
variable thumbDeltaY in my version to see what I did.